A life cycle environmental impact assessment of natural gas combined cycle thermal power plant in Andhra Pradesh, India

- GHG emissions from natural gas combined cycle thermal power plants using LCA
- A life cycle impact has been estimated for climate change, human health and ecosystem.
- Impacts on respiratory system is more from toxic organic compounds.
- ~81% GHG emissions are from combustion process and rest 19% from upstream process.

The study presents the life cycle environmental impacts of natural gas combined cycle thermal power plant in India. The CML 2001 and Eco-Indicator 99 (H) methods have been used to assess the midpoint and endpoint impacts from 'cradle to gate'. The primary data was collected by personal visits for environmental emissions, wastewater, fuel used, and technical specifications. The impacts category comprised of global warming, acidification, eutrophication, ecotoxicity, carcinogens, respiratory organics, respiratory inorganics and climate change. The study shows that upstream processes have more impacts except global warming potential if compared at mid-point stage. It is an interesting observation that ~81% of the total carcinogen impacts and ~88% of the respiratory-organics impacts in terms of disability adjusted life years are due to upstream process. This is due to the reason that during natural gas extraction, treatment and transmission, organic air emissions such as non-methane volatile organic compounds, formaldehyde and polycyclic aromatic hydrocarbons are released. Impacts on ecosystem quality are due to acidification & eutrophication together i.e. 2.27E-03 in terms of potentially disappeared fraction over a certain area and time frame (PDF×m2×yr) and 1.54E-03 as potentially affected fraction (PAF×m2×yr) due to ecotoxicity. This study shows that climate change potential contributes to 53% impacts on human health; whereas, human toxicity potential results into 47% impacts on human health. Acidification and eutrophication cause 60% impacts on species diversity, mainly for vascular plants and lower organisms; whereas, ecotoxicity results into 40% impacts on aquatic life.